Combine the first 6 ingredients in a medium bowl. Heat the oil in a wide skillet set over medium-high. When hot, add prawns and cook 1 minute per side, until pink and just cooked through. Transfer prawns to a plate.
Drain excess oil from the pan. Pour in the coconut milk mixture and bring to a simmer. Simmer 4 to 5 minutes, until lightly thickened. Season the sauce with salt. Add the prawns and cilantro to the sauce, heat through 1 or 2 minutes, and serve.
Note: To devein the prawns, use a small paring knife to make a lengthwise slit along the back of each peeled prawn. Pull out, or rinse out with cold water, the dark vein.
Options: Make coconut curry scallops by replacing the prawns with an equal amount of large scallops, patted dry. Use the same technique described for the prawns to cook the scallops. For a lower calorie version of this dish, use light coconut milk instead of regular. For added texture, sprinkle servings of the curry with a few coarsely chopped roasted, unsalted cashews or peanuts.